Color or light in science

Nighttime

Black can be defined as the visual impression experienced when no visible light reaches the eye. (This makes a contrast with whiteness, the impression of any combination of colors of light that equally stimulates all three types of color-sensitive visual receptors.)
Pigments that absorb light rather than reflect it back to the eye “look black”. A black pigment can, however, result from a combination of several pigments that collectively absorb all colors. If appropriate proportions of three primary pigments are mixed, the result reflects so little light as to be called “black”.
This provides two superficially opposite but actually complementary descriptions of black. Black is the lack of all colors of light, or an exhaustive combination of multiple colors of pigment. See also Primary colors

In physics, a black body is a perfect absorber of light, but, by a thermodynamic rule, it is also the best emitter. Thus, the best radiative cooling, out of sunlight, is by using black paint, though it is important that it be black (a nearly perfect absorber) in the infrared as well.
In elementary science, far Ultraviolet light is called “black light” because, unseen, it causes many minerals and other substances to fluoresce.
On January 16, 2008, researchers from Troy, New York’s Rensselaer Polytechnic Institute announced the creation of the darkest material on the planet. The material, which reflects only .045 percent of light, was created from carbon nanotubes stood on end. This is 1/30 of the light reflected by the current standard for blackness, and one third the light reflected by the previous record holder for darkest substance.[1]

Usage, symbolism, colloquial expressions

Authority and seriousness

In Japanese culture, kuro (black) is a symbol of nobility, age, and experience, as opposed to shiro (white), which symbolizes serfdom, youth, and naiveté. Thus the black belt is a mark of achievement and seniority in many martial arts, whereas in, for example, Shotokan karate, a white belt is a rank-less belt that comes before all other belts. These ranks are called dan.

Politics

The Lützow Free Corps, composed of volunteer German students and academics fighting against Napoleon in 1813, could not afford to make special uniforms and therefore adopted black, as the only color that could be used to dye their civilian clothing without the original color showing. As these volunteers were greatly praised and glorified by later revolutionaries, their choice of the black color might have influenced its later connotations.

Black is a common symbol of anarchism, originating as a symbol in the 1880s.

Sport

The national rugby union team of New Zealand is called the All Blacks, in reference to their black outfits, and the color is also shared by other New Zealand national teams such as the Black Caps (cricket) and the Kiwis (rugby league).

In baseball, “the black” refers to the batter’s eye, a blacked out area around the center-field bleachers, painted black to give hitters a decent background for pitched balls.

Ambiguity and secrecy

A black box is any device whose internal workings are unknown or inexplicable. In theatre, the black box is a smaller, undecorated theater whose auditorium and stage relationship can be configured in various way.

Beliefs, religions and superstitions

Black is a symbol of mourning and bereavement in Western societies, especially at funerals and memorial services. In some traditional societies, within for example Greece and Italy, widows wear black for the rest of their lives. In contrast, across much of Africa and parts of Asia, white is a color of mourning and is worn during funerals.

In English heraldry, black means darkness, doubt, ignorance, and uncertainty.[3]

Economy

To say one’s accounts are “in the black” is used to mean that one is or “no longer in the red”, or free of debt .

Being “in the red” is to be in debt—in traditional bookkeeping, negative amounts, such as costs, were printed in red ink, and positive amounts, like revenues, were printed in black ink, so that if the “bottom line” is printed in black, the firm is profiting.

Fashion

In Western fashion, black is considered stylish, sexy, elegant and powerful.

The colloquialism “X is the new black” is a reference to the latest trend or fad that is considered a wardrobe basic for the duration of the trend, on the basis that black is always fashionable. The phrase has taken on a life of its own as a snowclone, and has been stretched and parodied as a rhetorical device and a cliché.

Symbolic dualism with white

Black magic is a destructive or evil form of magic, often connected with death, as opposed to white magic. This was already apparent during Ancient Egypt when the Cush Tribe invaded Egyptian plantations along the Nile River.

Evil witches are stereotypically dressed in black and good fairies in white.

Black market is used to denote the trade of illegal goods, or alternatively the illegal trade of otherwise legal items at considerably higher prices, e.g. to evade rationing.

Black propaganda is the use of known falsehoods, partial truths, or masquerades in propaganda to confuse an opponent.

Blackmail is the act of threatening to reveal information about a person unless the threatened party fulfills certain demands. This information is usually of an embarrassing or socially damaging nature. Ordinarily, such a threat is illegal.

If the black eight-ball, in billiards, is sunk before all others are out of play, the player loses.

To blackball someone is to block their entry into a club or some such institution. In the traditional English gentlemen’s club, members vote on the admission of a candidate by secretly placing a white or black ball in a hat. If upon the completion of voting, there was even one black ball amongst the white, the candidate would be denied membership, and he would never know who had “blackballed” him.

Black tea in the Western culture is known as “crimson tea” in Chinese and culturally influenced languages, (紅茶, Mandarin Chinesehóngchá; Japanese kōcha; Korean hongcha), perhaps a more accurate description of the color of the liquid.